2.0l 16v erratic tickover

[bigbroony 0]

As title suggests my car has suddenly developed an erratic tickover.It starts and runs fine but sometimes the engine idles at 1500 to 2000 rpm.Usually however it either dies altogether or struggles to maintain 800.

Ihad this problem( or something like it) on my old SciroccoGTX.It turned out to be a by-pass valve that is open when cold but closes when warm actually staying open and allowing too much air in.

Is there such a thing on a Corrado?There's a likely looking ,grey plastic, cylindrical gizmo with a switch attached under the air intake elbow.

Any theories/help would be welcome before I ( gulp ) go professional.

 

Cheers Alan.

[nocrap 0]

Indeed there is, it's the black cylindrical thing on the right had side of the head with a couple of pipes and an electrical plug on it. its common(ish) for causing issues on the valvers. take it off and give it a good soak with carb cleaner!

[Chris 0]

my 2.0l 16v had this exact same problem last year. i replaced everything but the problem remained. i had an auto electrician look at it and he fixed it within 5 minutes. turned out the small adjuster pin on the throttle body was screwed too far in, so when the car started it was fine but as soon as it had been run for 5-10mins the revs jumped up and stayed at 1500-2000. i did play around with this when i was trying to fix it but didnt think it would be this simple so didnt focus on this point, the car was running fine before too, this problem just came out of the blue, this is why i didnt think it was the throttle body adjuster. all i had to do was unscrew the pin to allow minimal air through. sounds stupid but i missed it and it cost me £££. hope its this simple for you too, the problem youve described does sound the same as what i experienced last year.

 

good luck

[bigbroony 0]

Thanks for the replies.

 

Regarding the idle stabiliser valve; I knew you could clean the one on ethe Mk2 Golf( and indeed I have done )but wasn't sure about the one on the Corrado.I'll give that a try.

 

Where abouts is the screw on the throttle body? I can see what looks like a throttle stop screw. Is this the one you mean?

 

The problem started a couple of weeks ago. Just prior to that a lug on the oil filler cap snapped allowing oil to spray over the top of the cam cover.I naturally thought this was the problem, but after cleaning everything I can see I'm not so sure.

 

Cheers Alan.

[Chris 0]

yes thats the one i mean, its got an 8mm nut on it. screw it right the way out so its not holding the throttle body open at all and give it a go. i no it sounds really dumb but try it, it could save you some time and buck if its as simple as that.

[bigbroony 0]

The first thing I tried was screwing that in a bit to lift the revs and stop the engine dying.Then, on closer inspection, I found two vacuum pipes disconnected from undr the air intake elbow.I'll try screwing it out and see what effect that has.

 

Back to the idle stabilisation valve;is it supposed to buzz like the one fitted to Mk2 Golfs when the ignition's switched on?Because it doesn't.However, removing the connector when the idle's going bonkers calms things down a bit.

 

Alan.

[nocrap 0]

Mine buzzes.....

[bigbroony 0]

Mine doesn't buzz or vibrate, but there is a noticeable difference when it's disconnected.I don't yet know if thats a good or bad thing.

I can't make my mind up if its buzzing when the engine's running, but it doesn't when only the ignition is switched on